Trump’s rivals — combined with a cadre of outside groups either backing one of the other candidates or attacking Trump specifically — are spending more than $15 million in the two weeks leading up to the winner-take-all primary, according to a POLITICO analysis of television and radio advertising purchases.

But even as Rubio’s campaign acknowledges its supporters should vote for Kasich in Ohio to deny Trump, the outside-money cavalry isn’t following: Campaigns and groups are spending only $4.2 million over the same time period — with most of it coming from home-state Gov. John Kasich and his allies.

Part of the spending disparity is Florida’s larger population and bigger delegate haul. Florida has three media markets among the country’s 20 largest: Tampa (11th), Miami (16th) and Orlando (19th).

Another big part of the focus on Florida, however, is the fact that so much of the spending is driven by Conservative Solutions PAC, a super PAC supporting Marco Rubio as the first-term senator seeks a comeback victory in his home state to remain a viable GOP contender. Conservative Solutions PAC isn’t spending a dime in Ohio to hammer Trump,